For jellies I just take off seigan when I cast Drain. Both on ~1min timer so it works out pretty good. Orobon is a pain though, but in my ls we always chainstun bosses so it hardly gets tp moves off. As for killing faster, it's not just my /sam, but everyone that does it. If everyone's /nin, you lose 6hit and no meditate so you ws slower so the mob dies quite a bit slower. And really, a lot of mobs strip shadows and still do damage. Like the ones I listed earlier, and ones with multi-hit tp moves that seigan+TE absorbs completely, like Tri-clip. I don't see the reason for /nin in einherjar outside of Orobon boss, and even then he's not that common, and possibly low-manning einherjar.